package/kernel/mac80211/patches/302-ath9k-limit-retries-for-powersave-response-frames.patch

   1 From: Felix Fietkau <nbd@openwrt.org>
   2 Date: Thu, 2 Jul 2015 15:20:56 +0200
   3 Subject: [PATCH] ath9k: limit retries for powersave response frames
   4
   5 In some cases, the channel might be busy enough that an ath9k AP's
   6 response to PS-Poll frames might be too slow and the station has already
   7 gone to sleep. To avoid wasting too much airtime on this, limit the
   8 number of retries on such frames and ensure that no sample rate gets
   9 used.
  10
  11 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
  12 ---
  13
  14 --- a/drivers/net/wireless/ath/ath9k/xmit.c
  15 +++ b/drivers/net/wireless/ath/ath9k/xmit.c
  16 @@ -177,10 +177,25 @@ static void ath_send_bar(struct ath_atx_
  17  }
  18
  19  static void ath_set_rates(struct ieee80211_vif *vif, struct ieee80211_sta *sta,
  20 -                         struct ath_buf *bf)
  21 +                         struct ath_buf *bf, bool ps)
  22  {
  23 +       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(bf->bf_mpdu);
  24 +
  25 +       if (ps) {
  26 +               /* Clear the first rate to avoid using a sample rate for PS frames */
  27 +               info->control.rates[0].idx = -1;
  28 +               info->control.rates[0].count = 0;
  29 +       }
  30 +
  31         ieee80211_get_tx_rates(vif, sta, bf->bf_mpdu, bf->rates,
  32                                ARRAY_SIZE(bf->rates));
  33 +       if (!ps)
  34 +               return;
  35 +
  36 +       if (bf->rates[0].count > 2)
  37 +               bf->rates[0].count = 2;
  38 +
  39 +       bf->rates[1].idx = -1;
  40  }
  41
  42  static void ath_txq_skb_done(struct ath_softc *sc, struct ath_txq *txq,
  43 @@ -1462,7 +1477,7 @@ ath_tx_form_burst(struct ath_softc *sc,
  44                         break;
  45                 }
  46
  47 -               ath_set_rates(tid->an->vif, tid->an->sta, bf);
  48 +               ath_set_rates(tid->an->vif, tid->an->sta, bf, false);
  49         } while (1);
  50  }
  51
  52 @@ -1493,7 +1508,7 @@ static bool ath_tx_sched_aggr(struct ath
  53                 return false;
  54         }
  55
  56 -       ath_set_rates(tid->an->vif, tid->an->sta, bf);
  57 +       ath_set_rates(tid->an->vif, tid->an->sta, bf, false);
  58         if (aggr)
  59                 aggr_len = ath_tx_form_aggr(sc, txq, tid, &bf_q, bf);
  60         else
  61 @@ -1651,7 +1666,7 @@ void ath9k_release_buffered_frames(struc
  62                                 break;
  63
  64                         list_add_tail(&bf->list, &bf_q);
  65 -                       ath_set_rates(tid->an->vif, tid->an->sta, bf);
  66 +                       ath_set_rates(tid->an->vif, tid->an->sta, bf, true);
  67                         if (bf_isampdu(bf)) {
  68                                 ath_tx_addto_baw(sc, tid, bf);
  69                                 bf->bf_state.bf_type &= ~BUF_AGGR;
  70 @@ -2343,7 +2358,7 @@ int ath_tx_start(struct ieee80211_hw *hw
  71         if (txctl->paprd)
  72                 bf->bf_state.bfs_paprd_timestamp = jiffies;
  73
  74 -       ath_set_rates(vif, sta, bf);
  75 +       ath_set_rates(vif, sta, bf, ps_resp);
  76         ath_tx_send_normal(sc, txq, tid, skb);
  77
  78  out:
  79 @@ -2382,7 +2397,7 @@ void ath_tx_cabq(struct ieee80211_hw *hw
  80                         break;
  81
  82                 bf->bf_lastbf = bf;
  83 -               ath_set_rates(vif, NULL, bf);
  84 +               ath_set_rates(vif, NULL, bf, false);
  85                 ath_buf_set_rate(sc, bf, &info, fi->framelen, false);
  86                 duration += info.rates[0].PktDuration;
  87                 if (bf_tail)
  88 @@ -2898,7 +2913,7 @@ int ath9k_tx99_send(struct ath_softc *sc
  89                 return -EINVAL;
  90         }
  91
  92 -       ath_set_rates(sc->tx99_vif, NULL, bf);
  93 +       ath_set_rates(sc->tx99_vif, NULL, bf, false);
  94
  95         ath9k_hw_set_desc_link(sc->sc_ah, bf->bf_desc, bf->bf_daddr);
  96         ath9k_hw_tx99_start(sc->sc_ah, txctl->txq->axq_qnum);